Pincer counter to mini-chinese
When White is reluctant to allow Black a mini-chinese along this side, after can be tried. This side pattern is elaborated in a whole board context at Lei Fuseki.
The common way to play, in pro games, is for Black to make an enclosure with , or a.
That is, tenuki from the left corner is standard here. This leaves White free to continue with a tenuki joseki at a squared point (see 4-4 point low approach one-space low pincer, tenuki); but more normal is for White to play at the circled point first.
Recently the less usual way, jumping out with has been favoured by Kato Masao. Black can also invade at b.
This way of continuing goes against some preconceptions (the exchanges / and / are not according to conventional wisdom).
Clearly Black is trying for an early, dynamic development.
See also final diagram in preferring to pincer, for another case (the two-space high pincer).